Carburetor for liquefied gaseous fuels



Dec. 4, 1962 e. L. HOLZAPFEL CARBURETOR FOR LIQUEFIED GASEOUS FUELS 3 Sheets-Sheet 1 Filed March 16, 1959 m 0 MM y N2 w m 2 1H m T A m 0 QM De e. 4, 1962 G. HOLZAPFEL 3,067,020

CARBURETOR FOR LIQUEFIED GASEOUS FUELS Filed March 16, 1959 3 Sheets-Sheet 3' FIG. 10. A56

FIG. 9

INVENTOR. 6501965 A. Hagga -4 A TTO/ZNEY United States atent Ofifi C M enemas Patented Dec. a, was

CARBURETGZ non LHQUEEEEE) GASEGUS FUELS George L. l-llolzapfel, l ewbury Park, Calif assignor of eighty percent to Coneha Holzapfel, Newhury Park,

and twenty percent to Thomas P. Mahoney, Pacific lalisades, Qalif.

Filed Mar. 16, 1959, Ser. No. 799,529 13 Claims. (3. 43-184) This invention relates to a carburetor for liquefied gaseous fuels and, more particularly, to a carburetor which is adapted to reduce the pressure of said fuels and to mix the fuel and air in correct proportions for optimum combustion.

Conventional liquefied gaseous fuel carburetors are usually quite bulky and are associated with relatively large, separately mounted primary and secondary regulators adapted to successively reduce the pressure of the liquefied gaseous fuel and to mix the fuel at reduced pressure with combustion air. tended for use with liquefied gaseous fuels, it can be utilized with equal eifectiveness in conjunction with liquid fuels such as gasoline and the like and it is not intended that the scope of the utilization of the invention be limited to a particular fuel.

It is, therefore, an object of my invention to Provide a carburetor for liquefied gaseous fuels which eliminates the necessity for the provision of separate primary and secondary regulators and which is characterized by the fact that only one pressure regulator is utilized in conjunction with the fuel-air mixing chamber .of the carburetor. An associated objectof my invention is the provision of a carburetor of the aforementioned type where in the pressure regulator is incorporated in the housing of the carburetor as a unitary part thereof and wherein I the necessity for providing separate mountings for primary and secondary regulators is thus elerninated.

Another object of my invention is the provision of a carburetor for liquefied gaseous fuels which is of the selfstarting type, that is, which immediately upon the energization of the engine with which it is associated by a crank, self-starter, or other means, will automatically deliver fuel to the fuel-air mixing chamber of the carburetor, thus eliminating the necessity fcr solenoid-type and other starters conventionally associated with liquefied gaseous fuel carburetors.

A further object of my invention is the provision of a liquefied gaseous fuel carburetor which incorporates, in conjunction with the pressure regulator thereof, a fuel outlet valve, said fuel outlet valve being adapted to feed fuel at relatively high pressure to the fuel-air mixing chamber of the carburetor, thus radicially improving the performance of the carburetor and elim nating the necessity of the provision of the customarily supplied secondary regulator. Therefore, in the carburetor of my invention the fuel is subjected to only one stage of regulation and the customary secondary regulator is elimimated with consequent economies in cost of manufacture and consequent improvement in case of mounting the carburetor of my invention.

Another object of my invention is the provision of a carburetor for liquefied gaseous fuels wherein there is provided on the housing of the carburetor a pressureenergized actuator, said pressure-energized actuator being connected to both the aforementioned inlet valve and Althcugh the carburetor is primarily in the choke valve of the carburetor and said pressure actuator being also connected to the fuel-air mixing chamber of the carburetor, Therefore, when the pressure actuator is subjected to a pressure drop caused by energization of the engine with which the carburetor is associated, the actuator will automatically cause the opening of the choke valve and the concomitant opening of the fuel outlet valve, thus metering fuel to the fuelair mixing chamber in direct proportion to the amount of air fed past the choke of the carburetor. in this manner, the fuel-air mixture can be precisely calculated for all the choke openings and the outlet valve can be calibrated to accurately meter the fuel in an accurate proportion with the. amount of air passing into and through the fuel-air mixing chamber.

Another object of my invention is the provision of a carburetor of the aforementioned character which includes a housing formed in two symmetrical halves, said housing having opposed flat faces which are adapted to be secured in abutting relationship and having semi-circular faces which, when the fiat faces are secured in abutting relationship, define the fuel-air mixing chamber of the carburetor. The formation of the housing of the carburetor in two symmetrical halves in the above described manner also permits the choke and butterfly valves to have their spindle extremities disposed in bearings in the opposed flat faces, thus permitting the choke and throttle valve to be mounted as unItary parts during the assembly of the carburetor and thus eliminating the necessity for the elaborate mounting expedients customarily utilized in carburetors of the type under dfscussion here.

A further object of my invention is the provision of a pressure regulator inlet valve which includes a simple actuator constituted by a fiat spring, said flat or leaf spring having the inlet valve mounted upon one extremity thereof and associated with the inlet opening in said pressure regulator, said fiat spring being operatively engaged by the pressure reguiator diaphragm to cause displacement thereof and corresponding displacement or opening of the pressure inlet valve with which the flat spring is associated.

Other objects and advantages of my invention will be apparent from the following specification and the accompanying drawings which are for the purpose of illustration only and in which:

FIG. 1 is a perspective view showing a carburetor constructed in accordance with the teachings of my invention;

FIG. 2 is a side elevational view taken from the broken line 22 of FIG. 1;

FIG. 3 is a side elevational view taken from the broken line 3-4 of FIG. 1;

FIG. 4 is a fragmentary, sectional view showing the pressure actuator of the carburetor of my invention in part;

FIG. 5 is a vertical, sectional view taken on the broken line 55 of FIG. 1;

FIG. 6 is an enlar ed, fragmentary, sectional view taken on the broken line 66 of FIG. 5;

KG. 7 is a vertical, sectional view taken on the broken line 7-7 of FIG. 5;

FIG. 8 is an enlarged, longitudinal, sectional view of the fuel inlet valve incorporated-in the carburetor of my invention;

FIG. 9 is an exploded view showing the component parts of the carburetor of my invention; and

FIG. 10 is an enlarged, fragmentary, sectional view showing an alternative form of fuel outlet valve for use in the carburetor of my invention.

Referring to the drawings and particularly to FIGS. 1-3 thereof, 1 show a carburetor 1t] constructed in accordance with the teachings of my invention, said carburetor being embodied in a housing 12 which is formed from two symmetrically shaped parts, a first part 16 and a second part 18. The first part 16 is formed with flat mating faces 29 adapted to engage similar mating faces 22 provided upon the second part 18 and both the first part 16 and the second part 18 incorporate semicircularly formed walls 26 which, when the flat mating faces 26 and 22 are juxtaposed in abutting relationship, define a cylindrical fuel-air mixing chamber 26.

The flat mating faces 26 and 22 are provided with bearing recesses 28 adjacent the upper extremities of the parts 16 and 18 as shown in FIGS. 2 and 3 of the drawings, while said flat faces 26 and 22 incorporate bearing recesses 36 adjacent the lower extremities of the aforementioned parts. Therefore, when the fiat mating surfaces and 22 of the first and. second parts 16 and 18 of the carburetor housing 12 are juxtaposed in abutting relationship, the bearing recesses 28 and 30 cooperate to receive the spindles 32 and 34 of a choke and throttle valve 36 and 33, respectively.

Thus, the opposite extremities of the spindles 32 and 34 of the choke and throttle valves 36 and 38, respectively, can be deposited in the associated bearing recesses 28 and 3t) and, in this manner, these valves can be easily and cheaply assembled as component parts of the carburetor structure. Semi-circular mounting rings 40 incorporating mounting lugs 42 are formed upon the upper extremities of the parts 16 and 18 to facilitate the mounting of an air cleaner or similar auxiliary device in conjunction with the carburetor 10.

Each of the halves 16 and 18 of the housing 12 has a pressure chamber associated therewith, the first half 16 incorporating a first pressure chamber 44 and the second half 18 incorporating a second pressure chamber 46, as best shown in FIGS. 4-7 of the drawings. Each of the pressure chambers 44 and 46 has a cover 48 operatively associated therewith and maintained in operative relationship with the housing 12 by means of screws or similar fasteners 56. Adjustable fittings 52 are mounted in the covers 48 and incorporate orifices 54 establishing fluid communication between the interiors of the chambers 44 and 46 and the ambient air, for a purpose which will be described in greater detail below.

It will be noted that the lower extremity of each of the parts 16 and 18 of the housing 12 is provided with a mounting flange 58 to facilitate the securement of the carburetor 10 to the manifold or other portion of an associated engine, not shown.

The first pressure chamber 44 constitutes a pressure regulator and has a pressure responsive means constituted by a conventional diaphragm 60 mounted therein, said diaphragm being urgable in a right-hand direction, as best shown in FIGS. 5 and 6 of the drawings, by means of a spring 62 which has one extremity seated upon the center of the diaphragm and its opposite extremity seated in the associated fitting 52. By rotation of the fitting 52 in the appropriate direction, the compressive effect of the spring 62 upon the diaphragm 60 may be varied to accomplish the desired pressure reduction through the pressure regulator chamber 44.

A fuel inlet fitting 64 is mounted by means of screws 66 on the first part 16 of the housing 12 and has a valve seat 68 formed thereupon which is engageable by an inlet valve 70, as best shown in FIG. 6 of the drawings, to permit or restrict the flow of liquefied gaseous fuel into the pressure regulator chamber 44.

The energization of the inlet valve 76 is accomplished by a linkage 74 which, as best shown in FIGS. 5 and 6 of the drawings, includes a first bellcrank 76 and a second bellcrank 78 pivotally mounted with their juxtaposed legs in overlying and mutually engaging relationship. The lower extremity of the bellcrank 78 incorporates a bifurcated portion 36 which engages a yoke 82 on the diaphragm 60.

A valve member 84 formed from rubber or the like is mounted on the bellcrank. 76 and is urgable into engagement with the seat 68 on the fuel inlet fitting 64-. Since the spring 62 is normally compressed by the defiection of the diaphragm 60 in a left-hand direction, as viewed in FIGS. 5 and 6 of the drawings, due to the pressure in the chamber 44-, the bellcrank 78 urges the valve member 84 onto the seat 68, thus preventing further flow of liquefied gaseous fuel into the pressure chamber 44.

The pressure chamber 44 communicates, as best shown in FiGS. 2 and 5 of the drawings, with the mixing chamber 26 through a first bore 83, said first bore terminating, as best shown in FIG. 2 of the drawings, in a downwardly and angularly inclined outlet portion 91 which communicates with the mixing chamber 26 to discharge liquefied gaseous fuel downwardly thereinto.

Mounted in the first bore 63 is an outlet fuel valve 90, said outlet fuel valve being incorporated in an elongated housing 92 having a threaded extremity 94 adapted to engage a correspondingly threaded portion of the first bore 88 to retain said housing in said bore. The housing 92 incorporates a seat 5 6 against which the head 98 of a needle valve 166 is adapted to urge an O-ring 102. The needle valve 106 includes a tapered metering portion 104, as best shown in FIG. 8 of the drawings, and an elongated shank 106 formed integrally therewith.

A spring seat 108 is provided on the right-hand extremity of the elongated shank 106, as best shown in FIGS. 5 and 8 of the drawings, said spring seat being adapted to support one extremity of a compression spring 110 whose other extremity is mounted upon a shoulder 112 of the valve housing 92. The housing 92 is also provided with a shoulder 114 which, as best shown in FIG. 5 of the drawings, receives a sealing washer 116 which serves to seal the valve housing 92 against a corresponding portion of the carburetor housing 12.

The valve housing 92 is provided wtih an outlet chamber 120 in which the tapered metering portion 104 of the needle valve is located. A plurality of radial ports 118 communicates with said outlet chamber and thus permits fuel to be discharged laterally into right-angularly and downwardly oriented portion of the first bore 88.

A second bore 122 is formed in the second part 13 of the carburetor housing 12 and establishes fluid communication between the fuel-air mixing chamber 26 and the second pressure chamber 46. A third bore 124 is provided in the second part 18 of the carburetor housing 12 in alignment with the axially extending portion of the first bore and receives the portion of the valve housing 92 which projects beyond the axially extending portion of the first bore 88, as best shown in PEG. 5 of the drawings.

Therefore, the spring seat 1418 may be engaged by a yoke 128 mounted upon the pressure responsive diaphragm 131), as best shown in FIG. 5 of the drawings, so that the left-hand movement of the diaphragm 13%), as viewed in FIG. 5 of the drawings, will be accompanied by corresponding left-hand movement of the needle valve 100 urging the associated O-ring 102 off the seat 96 to permit flow of liquefied gaseous fuel under pressure into the fuel-air mixing chamber 26 of the carburetor, in a manner which will be described in greater detail below.

A spindle 134 has its opposite extremities journaled in the opposite walls of the second pressure chamber 46 and mounts a bifurcated lever 136 engageable with the yoke 128 on the pressure responsive diaphragm 130. The laterally projecting extremity of the spindle 134 is adapted to energize a linkage 14 9 operatively connecting the spindle 32 of the choke valve 36 to the pressure responsive diaphragm 130.

The outer extremity of the throttle valve spindle 34 has a throttle link 142 mounted thereupon which is engageable by any suitable means, such as a Bowden wire, to cause the opening of the throttle. A stop pin 144 is provided in the first part 16 of the carburetor housing 12 for engagement by a stop screw 1% and thus serves to limit rotation of the spindle 34 and thus rotation of the throttle 38 mounted thereupon.

An alternative construction 150 of the inlet valve is shown in FIG. 10 of the drawings as mounted within the first pressure chamber 44. In the alternative construction of the inlet valve 154' a simple fuel inlet fitting 152 is provided in a wall of the chamber 4-4 and has a valve seat 154 formed integrally therewith and projecting into the chamber 44. Mounted between spaced mounting blocks is a fiat or leaf spring actuator 16% which has a valve member 162 secured to an extremity thereof, one end of the valve member being beveled at 154 to permit it to pivot in a groove 166 in order that a rocking action may be imparted to the valve member 162 when the leaf spring let) is deflected to the right by corresponding right-hand movement of the pressure responsive diaphragm 61 as viewed in FIG. 10 of the drawmgs.

The alternative valve construction 15% is considerably simpler than the construction of the inlet valve 7% previously disclosed hereinabove and greatly reduces the cost of fabricating the carburetor of my invention.

The component parts of the carburetor housing 12 are best fabricated by the utilization of conventional die-casting processes since the first and second parts 1.6 and 1.8 can be cast with the first and second pressure chambers 4d and 45 formed therein and the covers 4-3 can be of identical configuration. In the assembly of the carburetor it? the spindles 32 and 3-4 of the choke valve 36 and throttle valve 38, respectively, are disposed in the respective bearing recesses 23 and 31] of the second part 13 of the housing 12 and the mating flat faces 26 and 22 of the parts 16 and 18 are brought into contiguity with each other after the valve housing 92. has its threaded portion 94 threaded into the correspondingly threaded portion of the first bore 88.

Of course, the other extremity of the valve housing 5 2, is inserted in the third bore 124 to permit the elongated shank ltlfi of the needle valve itltl to project into the second pressure chamber 35. Because of the fact that the housing 12 of the carburetor 15; is split on an axis which permits the mounting of the throttle and choke valves 36 and 38 and the outlet valve 9t) in the simple manner described, the cost of producing the carburetor 1d of my invention is materially reduced.

After the two parts 16 and 18 of the carburetor housing have been assembled with the other components of the carburetor in the above described manner, screws 168 are utilized to maintain the two parts in operative relationship with each other. Subsequently, the inlet valve fitting 64 is secured to the first part 16 of the housing 12 by means of the screws 66 and the inlet valve 7%} and the linkage 74 constituting a part thereof mounted in operative relationship with the first pressure chamber 44. The pressure responsive diaphragm 6% and the associated spring 62 are then mounted within the first pressure chamber 44 and the cover 48 secured in operative relationship with the pressure chamber by the utilization of the fastening screws 5%.

In a similar manner, the spindle 134 is located within the second pressure chamber 46 and the bifurcated lever 136 aflixed thereto, the pressure responsive diaphragm 134) being secured in juxtaposition thereto by means of the cover 43 and the associated mounting screws 5% therefor. After this is accomplished, the linkage 1 .0 between the spindle 134 and the choke Valve spindle 32 is installed and the throttle link 142 is also mounted upon the laterally extending portion of the throttle spindle 134. Therefore, it can be seen that once the component parts of the carburetor 141 of my invention have been assembled, the entire device is ready to be installed upon an engine by the utilization of the mounting flanges 58 and the elaborate starters and associated fuel regulators characteristic of prior art devices are eliminated. In addition, the simple assembly of the carburetor 1t materially reduces the cost of producing the same and results in a relatively small assembly which can be inserted in a much smaller space than prior art devices.

The assembly of the alternative inlet valve construction 1513 in the first pressure chamber 44 merely involves the disposition of the leaf spring 168 between the spaced mounting blocks 158 and the location of the beveled portion 164 of the valve member 162 in the groove 166 in juxtaposition to the valve seat 154. The opposite bent extremity of the leaf spring 160 is located in juxtaposition to the opposite wall of the first pressure chamber as. The assembly of the other components is similar to that described hereinabove.

In operation, the carburetor 10 is mounted upon the intake manifold of an internal combustion engine by the utilization of the mounting flanges 53. When so mounted, it constitutes a completely operative device independent of any auxiliary fittings, solenoid starters, or the like which are customarily utilized in conjunction with conventional gaseous fuel carburetors.

When the engine with which the carburetor 1G is associated is started by a manual or electrical means, the throttle valve 38 of the carburetor 1G is open and a negative pressure created within the fuel-air mixing chamber 26. When this occurs, a corresponding negative pres sure is created within the second pressure chamber 46 through the second bore 122 causing deflection of the pressure responsive diaphragm 139 to the left, as viewed in FIG. 5 of the drawings. The deflection of the pressure'responsive diaphragm in the above described manner causes corresponding axial movement of the needle valve 1% to unseat the 0-ring 1%2- from the seat 96 and permits flow of liquefied gaseous fuel under pressure from the first pressure chamber 44.

The flow of liquefied gaseous fuel from the chamber 44 permits right-hand movement of the pressure responsive diaphragm 6t} causing right-hand deflection of the lever 78, as viewed in FIG. 6 of the drawings, and permitting the bellcrank 76- to rotate in a counterclockwise direction to unseat the valve 70 and permit flow of liquefied gaseous fuel through the fuel inlet fitting 64.

The liquefied gaseous fuel is thus subjected to a single pressure reduction stage as it fiows through the pressure regulator constituted by the valve 76 and the associated first pressure chamber 44- and pressure responsive diaphragm 6t] and flows from said first pressure chamber past the unseated O-ring 162 and the tapered metering portion 1% of the needle valve 10% to the radial ports 11% in the needle valve housing 92. It will be observed from FIG. 2 of the drawings that the ports 118 discharge the liquefied gaseous fuel under pressure downwardly through the angularly and downwardly oriented outlet port 91 so that the downward direction imparted to the liquefied gaseous fuel as it enters the fuel-air mixing chamber 25 tends to accelerate the flow of combustion air into the fuel-air mixing chamber 26 and to create an optimum fuel mixture. It will be noted that the tapered metering portion 104 of the needle valve will be moved to the left as viewed in FIGS. 5 and 8 of the drawings as the throttle butterfly 33 is rotated to cause an increased negative pressure upon the pressure responsive diaphragm 13 9 to cause corresponding leftward movement of the needle valve ltltl.

The tapered metering portion 1M of the needle valve 7 too can be calculated to meter the proper amount of fuel to the fuelair mixing chamber '26 at all settings of throttle 38 and it will be noted that the position of choke butterfly 36 will correspond to that of t valve lilo at all times during the operation of t retor it When the engine with which the carburetor it: is shut down, 'the throttle butterfly 33 is, of course, returned to the closed position shown in FIG. 3 of the drawings and the air pressure in the chamber as returns to the ambient air pressure because of communication of the e amber with the ambient air past the choke butterfly 36. Wire this occurs, the pressure in the second pressure chamber 46 returns to ambient and the compression spring 315.? on the needle valve 10-9 causes simultaneous movement of the pressure responsive diaphragm res and the bifurca ed lever 135 to the right, as viewed in FIG. of the drawings, thus causing simultaneous impingement of the O- ring 102 of the needle valve it?!) on its associated seat and closure of the choke buterfiy as. Naturally, when the O-ring 102 seats in the above described manner, pressure in the first pressure chamber 44 on the right-hand side of the pressure responsive diaphragm 65), as viewed in FIGS. 5 and 6 of the drawings, will increase, caus 1g deflection thereof to the left against the bias of the compression spring 62 and returning the valve 7% to seated position on the associated valve seat 68 to terminate the flow of liquefied gaseous fuel from the fuel source through the fuel inlet fitting 64.

With the alternative embodiment of the pressure regulator valve construction shown in FIG. of the drawings, the valve member 162 is deflected from en agement with the valve seat 154 when a pressure drop occurs within the first chamber 4-4 due to the unseating of the 0-ring 162 from its seat 96. The unseating of the 0-ring 162 permits right-hand deflection of thefirst pressure responsive diaphragm 60 permitting the diaphragm to bend the leaf spring 160 at its center to rock the valve member 152 on its beveled extremity 164 in the groove 166. Conversely, when the needle valve rot; is closed to seat the O-ring 192 on the associated seat as, pressure built up in the first pressure chamber 44 will cause deflection of the diaphragm so to the left, as viewed in FIG. 1*) of the drawings, to permit the leaf spring ass to return to the straight position and rock the valve member 152, into seated position on the associated seat 154.

I thus provide by my invention a liquefied gaseous fuel carburetor which can be utilized with liquefied gaseous fuels of relatively high pressures such as propane and butane, or can be utilized with pressurized natural gases of somewhat lower pressures. The carburetor of invention eliminates the two pressure reduction conventionally utilized in con iunction with conventional liquefied gaseous fuel carburetors and is characterized also by the incorporation of the single stage pressure reducer or regulator in the body or housing of the carburetor it-- self. Furthermore, the fuel is fed at elevated pressures through a metering valve which coacts with the choke valve in response to pressure drops in the fuel-air mixing chamber to insure the proper fuel-air mixture for any throttle setting of the carburetor.

In addition; the carburetor of my invention is characterized by unique constructional features which facilitate the manufacture and assembly of the component parts of the carburetor, among them being the two-part split housing, the incorporation in the two parts of the housing of first and second pressure chambers, and the provision. in an alternative embodiment of the carburetor, of a simple, inexpensive and easily installed pressure regulator valve.

Other objects and advantages of the invention will, have been made apparent by the detailed disclosure appez hereinabove.

I claim:

1. In a carburetor, the combination: a housing having epo'zoao a fuel-air passage therein first chambers on sides thereof, said hou g 'ncor orating first and second bores respectively establishing ii 1 corn. tun cation between said first and'second chambers and said passage and a third bore in the wall of said secon' ber aligned with said first bore; a fuel inlet cornmur ing with said first chamber; first pressure responsive means in said first chamber; inlet valve means operatively con nected to said first pressure responsive me'ans ling fuel flow into said first chamber through s out at valve means mounted in said first bore or controlling fuel flow into said passage, said outlet valve means having a portion extending into said second chamber through said third bore; second pressure responsive means in said second chamber operatively connected to said outlet valve means; a choke valve mounted in said passage above said first, second, and third bores; a throttle valve mounted in said passage below said first, second and third bores; and a linkage operatively connecting said second pressure responsive means to said chol. valve to cause conjoint movement of said outlet valve and said choke valve.

2. In a carburetor, the combination of: a housing hav ing a passage incorporating a fuel-air mixing chamber defined by a choke valve at the upper extremity of said pas sage and a throttle valve at the lower extremity thereof, said housing incorporating first and second pressure responsive members and first and second bores establishing fluid communication between said mixing chamber and said members; a fuel inlet valve in said housing operatively' connected to said first pressure responsive member; anda fuel outlet Valve in said first bore operatively connected to said second pressure responsive member, said second pressure responsive member also being operatively connected to said choke valve whereby a pressure drop across said mixing chamber will cause conjoint movement of said outlet valve and said choke valve.

3. In a carburetor, the combination of: a housing having a passage incorporating a fuel-air mixing chamber defined by a choke valve at the upper extremity of said passage and a throttle valve at the lower extremity thereof, said housing incorporating a pressure responsive member and fuel inlet means and first and second bores respective ly establishing fluid communication between said fuel inlet means and said pressure responsive member and said mixing chamber; and a fuel outlet valve mounted in said first bore in communication with said fuel inlet means and operatively connected to said pressure responsive member, said pressure responsive member also being operatively connected to said choke valve whereby a pressure drop across said second bore will cause conjoint movement of said choke and outlet valves.

4. In a carburetor, the combination of: a housing consistin of mating halves having opposed flat surfaces engagin one another and spaced surfaces of semi-circular configuration between said fiat surfaces defining a fuel-air mixing chamber having upper and lower extremities in said housing; a choke valve mounted in the upper extremity of said chamber having a spindle with its extremities secured between said mating halves; and a throttle valve located at the lower extremity of said mixing chambe:- having a mounting spindle whose opposite extremities are secured between the opposed flat surfaces of said mating halves, said mating halves having opposed bores communicating with said chamber for the reception and control of a fuel outlet valve.

5. In a carburetor, the combination of: a housing consisting of mating halves having opposed fiat surfaces engaging one another and spaced surfaces of semi-circular configuration between said fiat surfaces defining a fuel-air mixing chamber in said housing, said housing having pres sure responsive means and fuel inlet means thereupon and first and second bores therein respectively establishing fluid communication between said mixing chamber and said fuel inlet means and said pressure responsive means; a choke valve mounted in the upper extremity of said chamber having a spindle with its extremities secured between said mating halves; a throttle valve located at the lower extremity of said mixing chamber having a mounting spindle whose opposite extremities are secured between the opposed flat surfaces of said mating halves; and a fluid outlet valve located in said first bore in communication with said fuel inlet means and operatively connected to said pressure responsive means and said choke valve whereby a pressure drop across said second bore will cause corresponding and conjoint opening of said outlet valve and said choke valve.

6. In a carburetor, the combination of: a housing consisting of mating halves having opposed flat surfaces engaging one another and spaced surfaces of semi-circular configuration between said flat surfaces defining a fuelair mixing chamber in said housing, said halves each incorporating pressure responsive means and a bore establishing fluid communication between said mixing chamber and said pressure responsive means; a choke valve mounted in the upper extremity of said chamber having a spindle with its extremities secured between said mating halves; a throttle valve located at the lower extremity of said mixing chamber having a mounting spindle whose opposite extremities are secured between the opposed flat surfaces of said mating halves; and a fuel outlet valve mounted in one of said bores for feeding fuel into said mixing chamber, said fuel outlet valve being fed fuel through said one of said pressure responsive means and being operatively connected to the other of said pressure responsive means and said choke whereby a pressure drop in said mixing chamber will energize said second pressure responsive means to cause conjoint movement of said outlet and choke valves.

7. In a carburetor, the combination of: a housing having a fuel-air mixing chamber therein and first and second chambers formed upon opposite sides thereof, said housing incorporating a first bore establishing fluid communication between said first chamber and said mixing chamber and a second bore establishing fluid communication between said second chamber and said mixing chamber and a third bore axially aligned with said first bore and extending into said second chamber; a choke valve at the upper extremity of said mixing chamber; a throttle valve at the lower extremity of said mixing chamber; pressure responsive means in said second chamber responsive to a pressure drop across said second bore; and a fuel outlet valve mounted in said first and third bores, said fuel outlet valve being operatively connected to said pressure responsive means and said pressure responsive means being operatively connected to said choke valve whereby pressure drop induced movement of said pressure responsive means will cause conjoint movement of said choke and outlet valves.

8. In a carburetor, the combination of: a housing having a fuel-air mixing chamber therein and a pressure chamber and a fuel inlet thereupon, said housing incorporating a first bore establishing fluid communication between said fuel inlet and said mixing chamber, a second bore establishing fluid communication between said pressure chamber and said mixing chamber and a third bore axially aligned with said first bore and extending into said pressure chamber; a throttle valve at the lower extremity of said mixing chamber; pressure responsive means in said pressure chamber responsive to a pressure drop across said second bore; and a fuel outlet valve mounted in said first and third bores, said fuel outlet valve being operatively connected to said pressure responsive means and said pressure responsive means being operatively connected to said choke valve whereby pressure drop induced movement of said pressure responsive means will cause conjoint movement of said choke and outlet valves.

9. In a carburetor, the combination of: a housing having a fuel-air mixing chamber therein, said mixing chamher having upper and lower extremities and,. said housing having first and second chambers formed therein and a fuel inlet communicating with said first chamber, said housing incorporating a first bore establishing fluid communication between said first chamber and said mixing chamber, a second bore establishing fluid communication between said second chamber and said mixing chamber and a third bore axially aligned with said first bore and extending into said second chamber; a choke valve at the upper extremity of said mixing chamber; a throttle valve at the lower extremity of said mixing chamber; first and second pressure responsive means in said first and second chambers; a fuel inlet valve operatively connected to said first pressure responsive means for controlling flow of fuel into said first chamber; and a fuel outlet valve mounted in said first and third bores, said fuel outlet valve being operatively connected to said first and second pressure responsive means and said second pressure responsive means being operatively connected to said choke valve whereby pressure drop induced movement of said first and second pressure responsive means will cause conjoint movement of said choke and outlet valves.

10. In a carburetor, the combination of: a housing having a mixing chamber and first and second pressure chambers formed therein on opposite sides thereof, said housing incorporating a first bore between said first chamber and said mixing chamber and second and third bores communicating with said second chamber, said housing having a fuel inlet into said first chamber; first and second pressure responsive means in said first and second chambers, respectively; a fuel inlet valve at said fuel inlet including an inlet valve member and a fiat spring actuator therefor in said first chamber, said first pressure responsive means being engageable with said flat spring actuator to move said inlet valve member; a choke valve at one extremity of said mixing chamber; a throttle valve at the other extremity thereof; and an outlet valve mounted in said first and third bores and being operatively connected to said second pressure responsive means and said second pressure responsive means being operatively connected to said choke valve.

11. in a carburetor, the combination of: a housing having a mixing chamber and first and second pressure chambers formed therein on opposite sides thereof, said housing incorporating a first bore between said first chamber and said mixing chamber and second and third bores communicating with said second chamber, said housing having a fuel inlet into said first chamber; first and second pressure responsive means in said first and second chambers, respectively; a fuel inlet valve at said fuel inlet including an inlet valve member and a flat spring actuator therefor in said first chamber, said first pressure responsive means being engageable with said flat spring actuator to move said inlet valve member; a choke valve at one extremity of said mixing chamber; a throttle valve at the other extremity thereof; and an outlet valve mounted in said first and third bores and being operatively connected to said second pressure responsive means and said second pressure responsive means being operatively connected to said choke valve and said outlet valve having a spring thereupon urging said outlet valve and choke valve into closed positions.

12. In a carburetor, the combination of: a housing having a pressure regulator on one side and a pressure actuator on the other side, said pressure regulator including a pressure responsive diaphragm, a fuel inlet and an inlet valve consisting of a spring urging a valve member on said fuel inlet, said pressure actuator including a pressure responsive diaphragm, said housing having a mixing chamber and a first bore between said pressure regulator and said mixing chamber and second and third bores communicating with said pressure actuator; a choke valve at one extremity of said mixing chamber; a throttle valve at the other extremity of said mixing chamber; and an outlet valve mounted in said first and third bores, said i. 1 outlet valve being operatively connected to said pressure actuator and said pressure actuator being connected to said choke valve.

13. In a carburetor, the combination of: a housing incorporating a fuel-air mixing chamber, a fuel inlet, pressure responsive means on one side of said mixing chamher and a first bore between said fuel mixing chamber and said fuel inlet, a second bore between said mixing chzmber and said pressure responsive means and a third bore communicating with said pressure responsive means; a choke valve at one extremity of said chamber operatively connected to said pressure responsive means; and a fuel outlet valve located in said first and third bores and References Cited in the file of this patent UNITED STATES PATENTS 2,597,335 Jones May 20, 1952 2,717,827 Best Sept. 13, 1955 2,831,758 Warner Apr. 22, 1958 2,855,283 Schumacher Oct. 7, 1958 2,957,492 Volpin Oct. 25, 1960 

5. IN A CARBURETOR, THE COMBINATION OF: A HOUSING CONSISTING OF MATING HALVES HAVING OPPOSED FLAT SURFACES ENGAGING ONE ANOTHER AND SPACED SURFACES OF SEMI-CIRCULAR CONFIGURATION BETWEEN SAID FLAT SURFACES DEFINING A FUEL-AIR MIXING CHAMBER IN SAID HOUSING, SAID HOUSING HAVING PRESSURE RESPONSIVE MEANS AND FUEL INLET MEANS THEREUPON AND FIRST AND SECOND BORES THEREIN RESPECTIVELY ESTABLISHING FLUID COMMUNICATION BETWEEM SAID MIXING CHAMBER AND SAID FURL INLET MEANS AND SAID PRESSURE RESPONSIVE MEANS; A CHOKE VALUE MOUNTED IN THE UPPER EXTREMITY OF SAID CHAMBER HAVING A SPINDLE WITH ITS EXTREMITIES SECURED BETWEEN SAID MATING HALVES; A THROTTLE VALVE LOCATED AT THE LOWER EXTREMITY OF SAID MIXING CHAMBER HAVING A MOUNTING SPINDLE WHOSE OPPOSITE EXTREMITIES ARE SECURED BE- 